1001001987 has 12 divisors (see below), whose sum is σ = 1446248544. Its totient is φ = 667170000.

The previous prime is 1001001923. The next prime is 1001002001. The reversal of 1001001987 is 7891001001.

It is not a de Polignac number, because 1001001987 - 2⁶ = 1001001923 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 1001001987.

It is not an unprimeable number, because it can be changed into a prime (1001001587) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 33237 + ... + 55737.

It is an arithmetic number, because the mean of its divisors is an integer number (120520712).

Almost surely, 2^1001001987 is an apocalyptic number.

1001001987 is a deficient number, since it is larger than the sum of its proper divisors (445246557).

1001001987 is a wasteful number, since it uses less digits than its factorization.

1001001987 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 27450 (or 27447 counting only the distinct ones).

The product of its (nonzero) digits is 504, while the sum is 27.

The square root of 1001001987 is about 31638.6154406289. The cubic root of 1001001987 is about 1000.3338841756. Note that the first 3 decimals are identical.

Adding to 1001001987 its reverse (7891001001), we get a palindrome (8892002988).

The spelling of 1001001987 in words is "one billion, one million, one thousand, nine hundred eighty-seven".